Description

Under funding from the Waste Management Research Center, now called the Illinois Sustainable Technology Center (ISTC), and the U.S. Department of Energy, the Energy & Environmental Research Center conceived of, verified, and optimized a two-step ozonolysis process on the bench scale for production of high-value chemicals derived from glycerol and cold-weather biodiesel additive derived from biodiesel. The first step of the process, which oxidizes glycerol into high-value chemicals, shows high conversion selectivity to valuable glyoxal in aqueous solution, based on limited tests. A by-product of this step consists of short-chain oxygenated carboxylic acids present as glyceryl esters. These acid by-products include glycolic acid, which is valuable in the cosmetics industry and as a raw material for production of biodegradable polymers. The glyceryl esters could be transesterified for recovery of the acids as methyl esters and the glycerol portion of the ester recycled for further conversion. The second step of the process yields a product with improved cold-weather properties relative to biodiesel. However, when the product is blended with biodiesel at ratios less than approximately 1:2, minimal effect on cloud point or pour point is observed. A brief economic assessment of the process suggests that the as-designed process would not be economical on a large scale. The process was designed inefficiently and could possibly be made economical with a better plant design. However, the expected selling price for the additive product from the second step would prohibit its use as a cold-weather biodiesel, and the process can only be made economical if the biodiesel ozonolysis step is removed.